MC33907 configuration after SW reset

[manuelaielo]

Hi,
I'm using a MPC5643L connected to MC33907 as SBC. The SBC has been configured and the WDT fed correctly. Starting a SW update procedure the WDT window is disabled, then a SW reset is performed by MPC5643L to jump in a section of code to perform the update, and where the SBC is not configured.

Which is the MC33907  expected behaviour after a MCU SW reset? Does it preserve the configuration?

I run the same code on KIT33908MBEVBE and seems that SBC configuration is preserved, but on ECU where the SBC is MC33907 seems that configuration are lost. In both cases the sbc is not in debug mode.

There are any difference between MC33907  and MC33908 behaviour after MCU SW reset?

Thank you in advance,

Best Regards

Manuela

[marco_sacchi]

Hi Manuela,

there aren't any difference between MC33907 and MC33908.The behavior of MC33907/8 is determined by the evolution of the two state machines (main state machine and fail state machine); some registers of se devices can be initialized only during a 256 msec window in the initialisation phase. You can check in the tables 15 and 16 in the device data sheet which are this registers. The other registers can be written during normal mode. According to the diagram of the fail safe state machine, an external reset will bring back from the normal watchdog to the INIT FS,  allowing the possibility to reinitialise the registers.

[manuelaielo]

Thank you very much for the answer.

BR,

Manuela